A pot, such as the pot in the pack in question, comprises a bottom wall, a side wall closed on itself, and a top closure. In a simple embodiment, the pot is in the shape of a cylinder or truncated cone and comprises a transverse flange near its top opening, the top closure being a flat seal lid integral with and secured to the flange. In other embodiments, the generatrix of the side wall is a line other than a straight line, having a more or less complex shape, and the directrix is other than a circle, for example a curved square with rounded corners. The side wall of such a pot is rounded to meet the bottom wall and allow for some vertical deformation of the pot under vertical compression. In other embodiments, the pot can stand upright when resting on its bottom wall which forms its base, the side wall being adapted to deform by elastic bending within a certain range of vertical compression.
In one embodiment, such a pot is made of thermoformed plastic and has a certain strength enabling it to be self-supporting, but the pot may be made of other materials and by other processes.
Such a pot is typically designed to contain a content that may or may not be homogeneous, in a more or less generally fluid state which does not exclude the presence of more or less solid lumps. Such content is, for example, a milk product or a dessert, although this is not an exhaustive list.
In one embodiment, the pot is designed to receive a single serving of such content for individual use, for example about a hundred grams, and in this case, it may have an approximate height of several centimeters and fit within a cylinder also having an approximate diameter of several centimeters. In other embodiments, the pot is intended for a smaller serving and is reduced in size, or conversely is intended for a bigger serving and is larger.
Depending on the case, the pots are separate or are connected together, for example by their flanges, to form a group of pots.
In one possible basic embodiment, the pack comprises a single layer of base pots having an even number of pots, for example four pairs side by side and next to one another. In other embodiments, the pack comprises multiple (two, three . . . ) stacked layers of pots—including the base layer and a top layer. In still other embodiments, a layer comprises more than four pots and optionally an odd number of pots, in particular arranged in three or more longitudinal rows and two or more transverse rows.
In a manner known in particular from document JP 2005 015019, a packaging of cardboard or the like in tubular shell form, for such a pack of pots, is created from a flat blank comprising:                side by side in a longitudinal direction: a top panel, two side panels, a base panel, a closure panel, and a securing means for closing the erected blank on itself,        transverse score lines, extending in a transverse direction substantially perpendicular to the longitudinal direction, suitable and intended for folding the panels, for erecting the blank, and for forming the packaging and the pack,        a receiving portion extending over a portion of the base panel, for receiving the bottom walls of the base pots.        
To enable transporting a large number of packs created in this manner, for example stacks of packs arranged inside a container, it is desirable to increase the vertical compressive strength of the packs in order to prevent damage to the pots of the packs forming the base of the stack.
It is therefore provided that the cardboard blank also comprises four sets of corner post panels which can be erected to form corner posts to provide the packaging with good vertical compressive strength.
In the embodiment described in JP 2005 015019, each set of corner post panels extends from a transverse end of a side panel, with longitudinal score lines that are suitable and intended for folding the panels of the sets of corner post panels in order to erect the sets of corner post panels and form the erected corner posts.
This way, vertical compression is absorbed by the erected corner posts and not solely by the pots of the pack. The vertical compressive strength is thus improved. However, it would be advantageous to increase this compressive strength in order to allow transporting and storing larger stacks of packs without damage.
Patent WO 2006/126873 discloses a cardboard container comprising vertical tubular corner posts having a triangular cross-section and a height at least two times greater than the perimeter of said cross-section. This increases the stiffness and strength of the container.
The prior art is also illustrated in documents WO 2010/096536, GB 1,049,681, GB 1,010,936, GB 2,196,608, and WO 2006/068523.
Starting from the creation of the flat blank, known for the indicated purpose, which has a generally rectangular shape and can be used to form the packaging for a pack, of the tubular shell type of cardboard or the like, the pack including at least one layer of base pots and, optionally, one or more layers of pots stacked vertically on top of the layer of base pots, the blank comprising: side by side in a longitudinal direction, a top panel, two side panels, a base panel, a closure panel, and a securing means for closing the erected blank on itself; transverse score lines extending in a transverse direction substantially perpendicular to the longitudinal direction, suitable and intended for folding the panels, for erecting the blank, and for forming the packaging and the pack; four sets of corner post panels, each set of corner post panels extending from a transverse end of a side panel and able to be erected relative to said side panel so as to form an erected corner post; longitudinal score lines, suitable and intended for folding the panels of the sets of corner post panels, for erecting the sets of corner post panels, and for forming the erected corner posts; a receiving portion extending over a portion of the base panel, for receiving the bottom walls of the base pots; the problem underlying the invention is to improve the vertical compressive strength of the pack packaging. This problem also concerns high machinability at high speeds, with a reliable method and a production line which eliminates disadvantageous complexities.
A description of the invention as characterized is provided below.